Multiple plants I'm anxious about

[Longroots]

Since my reliable Coelogyne Fimbriata has been funky recently, it's made me examine some plants more closely. Out of my collection, my concerns are the images attached, which have been labeled what species they are.

Firstly, I grow all of them in semi hydroponics, so I suspect Ray will be able to help a lot. I also must admit my fertilisation using an NPK blend has been abysmal, however my cal-mag routine has been OK.

All are under grow lights, with varying intensities. The Aeridis for example recieves a good blast of light, however the Bulbophyllum obviously recieves less.

I think that all the photographed issues speak for themselves. The Coelgyne worried me however as the black spots were slightly indented, and are also in a curiously rounded formation.

I will say, I've had the Aeridis for a number of years, and it has always been dramatic, and always had these large black spots appearing. The yellowing however is from light overexposure. I know that because I put it in a brighter location, and then it yellowed a bit.

Sorry for always resorting here for my problems, but I appreciate the support. I have also got a 7-2-5 NPK fertiliser I'm now using, and I'm mixing that with cal-mag for about a 180 tds concentration.